// NOTICE!! DO NOT USE ANY OF THIS JAVASCRIPT
// IT'S JUST JUNK FOR OUR DOCS!
// ++++++++++++++++++++++++++++++++++++++++++
/*!
 * Copyright 2014 Twitter, Inc.
 *
 * Licensed under the Creative Commons Attribution 3.0 Unported License. For
 * details, see http://creativecommons.org/licenses/by/3.0/.
 */
// Intended to prevent false-positive bug reports about Bootstrap not working properly in old versions of IE due to folks testing using IE's unreliable emulation modes.
(function () {
    'use strict';

    function emulatedIEMajorVersion() {
        var groups = /MSIE ([0-9.]+)/.exec(window.navigator.userAgent)
        if (groups === null) {
            return null
        }
        var ieVersionNum = parseInt(groups[1], 10)
        var ieMajorVersion = Math.floor(ieVersionNum)
        return ieMajorVersion
    }

    function actualNonEmulatedIEMajorVersion() {
        // Detects the actual version of IE in use, even if it's in an older-IE emulation mode.
        // IE JavaScript conditional compilation docs: http://msdn.microsoft.com/en-us/library/ie/121hztk3(v=vs.94).aspx
        // @cc_on docs: http://msdn.microsoft.com/en-us/library/ie/8ka90k2e(v=vs.94).aspx
        var jscriptVersion = new Function('/*@cc_on return @_jscript_version; @*/')() // jshint ignore:line
        if (jscriptVersion === undefined) {
            return 11 // IE11+ not in emulation mode
        }
        if (jscriptVersion < 9) {
            return 8 // IE8 (or lower; haven't tested on IE<8)
        }
        return jscriptVersion // IE9 or IE10 in any mode, or IE11 in non-IE11 mode
    }

    var ua = window.navigator.userAgent
    if (ua.indexOf('Opera') > -1 || ua.indexOf('Presto') > -1) {
        return // Opera, which might pretend to be IE
    }
    var emulated = emulatedIEMajorVersion()
    if (emulated === null) {
        return // Not IE
    }
    var nonEmulated = actualNonEmulatedIEMajorVersion()

    if (emulated !== nonEmulated) {
        window.alert('WARNING: You appear to be using IE' + nonEmulated + ' in IE' + emulated + ' emulation mode.\nIE emulation modes can behave significantly differently from ACTUAL older versions of IE.\nPLEASE DON\'T FILE BOOTSTRAP BUGS based on testing in IE emulation modes!')
    }
})();
